1. Field
The present invention relates to equipment for manufacturing a flat display panel, and more particularly, to an apparatus for attaching substrates of a flat display panel to one another.
2. Background
With the advancement of an information society, there has been a growing demand for various types of displays. Recently, various types of flat displays, such as liquid crystal displays (LCDs), plasma display panels (PDPs), electroluminescent displays (ELDs) and vacuum fluorescent displays (VFDs), have been developed, some of which are already widely used in real life. In particular, LCDs are widely used as portable image displays, and they are replacing cathode ray tubes (CRTs) because they are lighter and thinner, and also have higher image quality and consume less power than CRTs.
A conventional LCD is formed by injecting liquid crystals between a thin film transistor (TFT) substrate having electrodes and a color filter (CF) substrate coated with phosphors. To manufacture an LCD, after a TFT substrate and a CF substrate are fabricated separately, they must be attached to each other, and a liquid crystal material must be injected into space between the attached substrates. The process of attaching the substrates is one of the most important processes that determine the quality of the LCD. A sealer is deposited on an outer circumferential surface of each of the TFT and CF substrates to prevent leakage of liquid crystal material, and a spacer is interposed between the TFT and CF substrates to maintain a predetermined gap between them.
An apparatus for attaching substrates typically includes upper and lower chambers which can create a vacuum state therein, and such technology is disclosed in detail in Korean Patent Publication Nos. 10-2005-0004698 and 10-2005-0064139. In this apparatus, a lower chamber is fixed, and an upper chamber, which can be lowered toward the lower chamber, is installed above the lower chamber. Therefore, the gap between substrates respectively attached to the upper and lower chambers is controlled by moving the substrate attached to the upper chamber downward. Alignment of the substrates is controlled by moving the substrate attached to the lower chamber.
Each of the upper and lower chambers includes parts such as a table, a chuck stage, a chuck and an aligner. The parts are designed to prevent harm or deformation of the substrate, and they also control the alignment and gap between the substrates. The parts are coupled to one another by couplers, such as bolts included in each chamber.
However, in the apparatus having the upper and lower chambers structured as described above, particles remaining in the upper chamber may enter the lower chamber as the upper chamber is lowered toward the lower chamber, thereby deteriorating substrate quality. In addition, as the upper chamber is moved, the alignment of the upper and lower chambers, the alignment of the substrates, and the gap between the substrates are changed, which, in turn, changes an attachment environment.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.